can any one plz solve this!!!!

[aloha]

The price of a TV in 1970 increased by 300% in 1980. The price of
the 1980 model TV increased by 200% in 1990. By what percentage
did the price increase from 1970 to 1990?
A 500% B 600%
C 900% D 1100%

answer is D somehow...........

 

[marie_knox]

It should be A